VTechWorks Repository :: Browsing by Author "Huber, Patrick"

Browsing by Author "Huber, Patrick"

Now showing 1 - 20 of 50

The 2010 Interim Report of the Long-Baseline Neutrino Experiment Collaboration Physics Working Groups
Collaboration, TLBNE; Akiri, T.; Allspach, D.; Andrews, M.; Arisaka, K.; Arrieta-Diaz, E.; Artuso, M.; Bai, X.; Balantekin, A. B.; Baller, B.; Barletta, W. A.; Barr, G.; Bass, M.; Beck, A.; Becker, B.; Bellini, V.; Benhar, Omar; Berger, B. E.; Bergevin, M.; Berman, E.; Berns, H.; Bernstein, A.; Beroz, F.; Bhatnagar, V.; Bhuyan, B.; Bionta, R.; Bishai, M.; Blake, A.; Blaufuss, E.; Bleakley, B.; Blucher, E.; Blusk, S.; Boehnlein, D.; Bolton, T.; Brack, J.; Bradford, R.; Breedon, R.; Bromberg, C.; Brown, R.; Buchanan, N.; Camilleri, Leslie; Campbell, M.; Carr, Rachel E.; Carminati, G.; Chen, A.; Chen, H.; Cherdack, D.; Chi, C.; Childress, S.; Choudhary, B.; Church, E.; Cline, D.; Coleman, S.; Corey, R.; D'Agostino, M. V.; Davies, G. S.; Dazeley, S.; Jong, J. D.; DeMaat, B.; Demuth, D.; Dighe, A.; Djurcic, Zelimir; Dolph, J.; Drake, G.; Drozhdin, A.; Duan, H.; Duyang, H.; Dye, S.; Dykhuis, T.; Edmunds, D.; Elliott, S.; Enomoto, S.; Escobar, C. O.; Felde, J.; Feyzi, F.; Fleming, B.; Fowler, J.; Fox, W.; Friedland, A.; Fujikawa, B. K.; Gallagher, H.; Garilli, G.; Garvey, G. T.; Gehman, V. M.; Geronimo, G. D.; Gill, R.; Goodman, M.; Goon, J.; Gorbunov, D.; Gran, R.; Guarino, V.; Guarnaccia, E.; Guenette, R.; Gupta, P.; Habig, A.; Hackenburg, R. W.; Hahn, A.; Hahn, R.; Haines, T.; Hans, S.; Harton, J.; Hays, S.; Hazen, E.; He, Q.; Heavey, A.; Heeger, K.; Hellauer, R.; Himmel, A.; Horton-Smith, Glenn A.; Howell, J.; Huber, Patrick; Hurh, P.; Huston, J.; Hylen, J.; Insler, J.; Jaffe, D.; James, C.; Johnson, C.; Johnson, M.; Johnson, R.; Johnson, W.; Johnston, W.; Johnstone, J.; Jones, B.; Jostlein, H.; Junk, T.; Junnarkar, S.; Kadel, R.; Kafka, T.; Kaminski, D.; Karagiorgi, Georgia S.; Karle, A.; Kaspar, J.; Katori, T.; Kayser, B.; Kearns, E.; Kettell, S. H.; Khanam, F.; Klein, J.; Kneller, J.; Koizumi, G.; Kopp, J.; Kopp, S.; Kropp, W.; Kudryavtsev, V. A.; Kumar, A.; Kumar, J.; Kutter, T.; Lackowski, T.; Lande, K.; Lane, C.; Lang, K.; Lanni, F.; Lanza, R.; Latorre, T.; Learned, J.; Lee, D.; Lee, K.; Li, Y.; Linden, S.; Ling, J.; Link, Jonathan M.; Littenberg, L.; Loiacono, L.; Liu, T.; Losecco, J.; Louis, W.; Lucas, P.; Lunardini, C.; Lundberg, B.; Lundin, T.; Makowiecki, D.; Malys, S.; Mandal, S.; Mann, A.; Mantsch, P.; Marciano, W. J.; Mariani, Camillo; Maricic, Jelena; Marino, A.; Marshak, M.; Maruyama, R.; Matthews, J.; Matsuno, S.; Mauger, C.; McCluskey, E.; McDonald, K.; McFarland, K. S.; McKeown, R.; McTaggart, R.; Mehdiyev, R.; Melnitchouk, W.; Meng, Y.; Mercurio, B.; Messier, M.; Metcalf, W.; Milincic, R.; Miller, W.; Mills, G.; Mishra, S.; MoedSher, S.; Mohapatra, D.; Mokhov, N.; Moore, C.; Morfin, J.; Morse, W.; Moss, A.; Mufson, S.; Musser, J.; Naples, D.; Napolitano, J.; Newcomer, M.; Norris, B.; Ouedraogo, S.; Page, B.; Pakvasa, S.; Paley, J.; Paolone, V.; Papadimitriou, V.; Parsa, Z.; Partyka, K.; Pavlovic, Z.; Pearson, C.; Perasso, S.; Petti, R.; Plunkett, R.; Polly, C. C.; Pordes, S.; Potenza, R.; Prakash, A.; Prokofiev, O.; Qian, X.; Raaf, J.; Radeka, V.; Raghavan, R.; Rameika, R.; Rebel, B.; Rescia, S.; Reitzner, D.; Richardson, M.; Riesselmann, K.; Robinson, M.; Rosen, M.; Rosenfeld, C.; Rucinski, R.; Russo, T.; Sahijpal, S.; Salon, S.; Samios, N.; Sanchez, Maria Cristina; Schmitt, R.; Schmitz, D.; Schneps, J.; Scholberg, K.; Seibert, S.; Sergiampietri, F.; Shaevitz, Marjorie Hansen; Shanahan, P.; Shaposhnikov, M.; Sharma, R.; Simos, N.; Singh, V.; Sinnis, G.; Sippach, W.; Skwarnicki, T.; Smy, M.; Sobel, H.; Soderberg, M.; Sondericker, J.; Sondheim, W.; Spitz, Joshua; Spooner, N.; Stancari, M.; Stancu, Ion; Stewart, J.; Stoler, P.; Stone, J.; Stone, S.; Strait, J.; Straszheim, T.; Striganov, S.; Sullivan, G.; Svoboda, R.; Szczerbinska, B.; Szelc, A.; Talaga, R.; Tanaka, H.; Tayloe, R.; Taylor, D.; Thomas, J.; Thompson, L.; Thomson, M.; Thorn, C.; Tian, X.; Toki, W.; Tolich, N.; Tripathi, M.; Trovato, M.; Tseung, H.; Tzanov, M.; Urheim, J.; Usman, S.; Vagins, M. R.; Berg, R. V.; Water, R. V. D.; Varner, G.; Vaziri, K.; Velev, G.; Viren, B.; Wachala, T.; Walter, C.; Wang, H.; Wang, Z.; Warner, D.; Webber, D.; Weber, A.; Wendell, R.; Wendt, C.; Wetstein, M.; White, H.; White, S.; Whitehead, L.; Willis, W.; Wilson, R. J.; Winslow, L.; Ye, J.; Yeh, M.; Yu, B.; Zeller, Geralyn P.; Zhang, C.; Zimmerman, E.; Zwaska, R. (2011-10-27)
In early 2010, the Long-Baseline Neutrino Experiment (LBNE) science collaboration initiated a study to investigate the physics potential of the experiment with a broad set of different beam, near- and far-detector configurations. Nine initial topics were identified as scientific areas that motivate construction of a long-baseline neutrino experiment with a very large far detector. We summarize the scientific justification for each topic and the estimated performance for a set of far detector reference configurations. We report also on a study of optimized beam parameters and the physics capability of proposed Near Detector configurations. This document was presented to the collaboration in fall 2010 and updated with minor modifications in early 2011.
Annual Modulation Measurement of the Low Energy Solar Neutrino Flux with the Borexino Detector
Manecki, Szymon M. (Virginia Tech, 2013-06-20)
This work reports a first attempt to measure the solar neutrino annual
flux modulation due to Earth\'s elliptical orbit with the Borexino detector. Borexino is a real-time calorimetric detector for low energy neutrino spectroscopy located in the underground laboratory of Gran Sasso, Italy. The experiment\'s main focus is the direct measurement of the 7Be solar neutrino flux of all flavors via neutrino-electron scattering in an ultra-pure scintillation liquid. The original goal of this work was to quantify sensitivity of the Borexino detector to a 7% peak-to-peak signal variation over the course of a year and study background stability. A Monte-Carlo simulated sample of the expected variation was prepared in two phases of data acquisition, Phase I that spans from May-2007 to May-2010 and Phase II from October-2011 to September-2012. The data was then fitted in the time domain with a sinusoidal function and analyzed with the Lomb-Scargle fast Fourier transformation in the search for significant periodicities between periods of 0.5 and 1.5 years. The search was performed in the energy window dominated by 7Be, [210; 760] keV, and 60-day bins in the case of the fit and 10-bins for the Lomb-Scargle scan. This work also contains study of the post-purification data of Phase II beyond September-2012 with a prediction for the future sensitivity and justification of the achieved background levels.
Antineutrino detection based on heterogeneous scintillation lattice
(United States Patent and Trademark Office, 2019-10-01)
A radiation detector and detection method comprising one or more antineutrino capture sections having a plurality of cells. The cells including hydrogen, act as scintillators and contain a wavelength shifter. Also included are a plurality of neutron capture layers containing a neutron capture agent. The cells are disposed between said neutron capture layers. The layers act as scintillators to convert the radiation emission of a neutron capture to light for transmission to at least one of the cells and the cells and layers have different scintillation time constants.
Applications of Neutrino Physics
Christensen, Eric Kurt (Virginia Tech, 2014-09-02)
Neutrino physics has entered a precision era in which understanding backgrounds and systematic uncertainties is particularly important. With a precise understanding of neutrino physics, we can better understand neutrino sources. In this work, we demonstrate dependency of single detector oscillation experiments on reactor neutrino flux model. We fit the largest reactor neutrino flux model error, weak magnetism, using data from experiments. We use reactor burn-up simulations in combination with a reactor neutrino flux model to demonstrate the capability of a neutrino detector to measure the power, burn-up, and plutonium content of a nuclear reactor. In particular, North Korean reactors are examined prior to the 1994 nuclear crisis and waste removal detection is examined at the Iranian reactor. The strength of a neutrino detector is that it can acquire data without the need to shut the reactor down. We also simulate tau neutrino interactions to determine backgrounds to muon neutrino and electron neutrino measurements in neutrino factory experiments.
Applied Antineutrino Physics 2015 -- Conference Summary
Bowden, N. S.; Heeger, K. M.; Huber, Patrick; Mariani, Camillo; Vogelaar, R. Bruce (2016-02)
This is a brief summary of the 11th Applied Antineutrino Physics 2015 workshop held at the Virginia Tech Arlington Research Facility from December 7-8, 2015.
Aspects of Supersymmetry
Jia, Bei (Virginia Tech, 2014-04-21)
This thesis is devoted to a discussion of various aspects of supersymmetric quantum field theories in four and two dimensions. In four dimensions, 𝒩 = 1 supersymmetric quantum gauge theories on various four-manifolds are constructed. Many of their properties, some of which are distinct to the theories on flat spacetime, are analyzed. In two dimensions, general 𝒩 = (2, 2) nonlinear sigma models on S² are constructed, both for chiral multiplets and twisted chiral multiplets. The explicit curvature coupling terms and their effects are discussed. Finally, 𝒩 = (0, 2) gauged linear sigma models with nonabelian gauge groups are analyzed. In particular, various dualities between these nonabelian gauge theories are discussed in a geometric content, based on their Higgs branch structure.
Calibration of the COHERENT Neutrino Flux Normalization Detector
Tellez-Giron-Flores, Karla Rosita (Virginia Tech, 2023-11-14)
Neutrinos hold the promise of untangling many unresolved questions in particle physics. Their unique properties and behaviors offer a distinctive window into understanding the fundamentals of the universe, potentially providing answers to some of the most deep puzzles in modern physics. CEνNS, or Coherent Elastic Neutrino-Nucleus Scattering, is a process where a neutrino interacts with an atomic nucleus and scatters away, leaving the nucleus to recoil. CEνNS is an important area of study for understanding neutrino properties as well as their role in the universe. The COHERENT collaboration was the first to measure CEνNS, using neutrinos from the Spallation Neutron Source (SNS). The direct measurement of the SNS neutrino flux is vital for the precision of CEνNS measurements. This work introduces the latest addition to the COHERENT's armory –a D2O detector specifically designed to measure the SNS neutrino flux. In the present dissertation, the emphasis is made on the steps taken to operationalize COHERENT's D2O detector. This work unfolds the intensive simulation work directed to determine the detector's optimal design, ensuring it stands strong to the demands of neutrino physics experiments. Establishing the detector's calibration is essential to its operational phase. A dedicated calibration system, described in detail in this work, has been developed, utilizing encapsulated LED flashers controlled by a microcontroller unit to ensure the systematic and reliable calibration of the detector. A significant portion of the document is devoted to the calibration analysis, where we use Michel electrons to obtain an energy scale for the detector, thereby ensuring the reliability and accuracy of the future neutrino flux measurements.
Cerium Ruthenium Low-Energy Antineutrino Measurements for Safeguarding Military Naval Reactors
Cogswell, Bernadette K.; Huber, Patrick (American Physical Society, 2022-06-14)
The recent agreement to transfer nuclear submarine reactors and technology from two nuclear-weapon states to a non-nuclear-weapon state (AUKUS deal) highlights an unsolved problem in international safeguards: how to safeguard naval reactor fuel while it is on board an operational nuclear submarine. Proposals to extend existing safeguards technologies and practices are complicated by the need for civilian international inspectors to gain access to the interior of the submarine and the reactor compartment, which raises national security concerns. In this Letter we show that implementing safeguards on submarine propulsion reactors using a low-energy antineutrino reactor-off method, between submarine patrols, can by-pass the need for onboard access all together. We find that, using inverse beta decay, detectors can achieve a timely and high level of assurance that a submarine???s nuclear core has not been diverted (detector mass of around 100 kg) nor its enrichment level changed (detector mass of around 10 tons).
Chiral Rings of Two-dimensional Field Theories with (0,2) Supersymmetry
Guo, Jirui (Virginia Tech, 2017-04-26)
This thesis is devoted to a thorough study of chiral rings in two-dimensional (0,2) theories. We first discuss properties of chiral operators in general two-dimensional (0,2) nonlinear sigma models, both in theories twistable to the A/2 or B/2 model, as well as in non-twistable theories. As a special case, we study the quantum sheaf cohomology of Grassmannians as a deformation of the usual quantum cohomology. The deformation corresponds to a (0,2) deformation of the nonabelian gauged linear sigma model whose geometric phase is associated with the Grassmannian. Combined with the classical result, the quantum ring structure is derived from the one-loop effective potential. Supersymmetric localization is also applicable in this case, which proves to be efficient in computing A/2 correlation functions. We then compute chiral operators in general (0,2) nonlinear sigma models, and apply them to the Gadde-Gukov-Putrov triality proposal, which says that certain triples of (0,2) GLSMs should RG flow to nontrivial IR fixed points. As another application, we extend previous works to construct (0,2) Toda-like mirrors to the sigma model engineering Grassmannians.
Combining dark matter detectors and electron-capture sources to hunt for new physics in the neutrino sector
Coloma, Pilar; Huber, Patrick; Link, Jonathan M. (Springer, 2014-11-10)
In this letter we point out the possibility to study new physics in the neutrino sector using dark matter detectors based on liquid xenon. These are characterized by very good spatial resolution and extremely low thresholds for electron recoil energies. When combined with a radioactive nu e source, both features in combination allow for a very competitive sensitivity to neutrino magnetic moments and sterile neutrino oscillations. We find that, for realistic values of detector size and source strength, the bound on the neutrino magnetic moment can be improved by an order of magnitude with respect to the present value. Regarding sterile neutrino searches, we find that most of the gallium anomaly could be explored at the 95% confidence level just using shape information.
Comparison of the calorimetric and kinematic methods of neutrino energy reconstruction in disappearance experiments
Ankowski, Artur M.; Benhar, Omar; Coloma, Pilar; Huber, Patrick; Jen, C. M.; Mariani, Camillo; Meloni, David; Vagnoni, E. (American Physical Society, 2015-10-22)
To be able to achieve their physics goals, future neutrino-oscillation experiments will need to reconstruct the neutrino energy with very high accuracy. In this work, we analyze how the energy reconstruction may be affected by realistic detection capabilities, such as energy resolutions, efficiencies, and thresholds. This allows us to estimate how well the detector performance needs to be determined a priori in order to avoid a sizable bias in the measurement of the relevant oscillation parameters. We compare the kinematic and calorimetric methods of energy reconstruction in the context of two ν_μ &8594; ν_μ disappearance experiments operating in different energy regimes. For the calorimetric reconstruction method, we find that the detector performance has to be estimated with an Ο(10%) accuracy to avoid a significant bias in the extracted oscillation parameters. On the other hand, in the case of kinematic energy reconstruction, we observe that the results exhibit less sensitivity to an overestimation of the detector capabilities.
Corrections to and Applications of the Antineutrino Spectrum Generated by Nuclear Reactors
Jaffke, Patrick John (Virginia Tech, 2015-11-16)
In this work, the antineutrino spectrum as specifically generated by nuclear reactors is studied. The topics covered include corrections and higher-order effects in reactor antineutrino experiments, one of which is covered in Ref. [1] and another contributes to Ref. [2]. In addition, a practical application, antineutrino safeguards for nuclear reactors, as summarized in Ref. [3,4] and Ref. [5], is explored to determine its viability and limits. The work will focus heavily on theory, simulation, and statistical analyses to explain the corrections, their origins, and their sizes, as well as the applications of the antineutrino signal from nuclear reactors. Chapter [1] serves as an introduction to neutrinos. Their origin is briefly covered, along with neutrino properties and some experimental highlights. The next chapter, Chapter [2], will specifically cover antineutrinos as generated in nuclear reactors. In this chapter, the production and detection methods of reactor neutrinos are introduced as well as a discussion of the theories behind determining the antineutrino spectrum. The mathematical formulation of neutrino oscillation will also be introduced and explained. The first half of this work focuses on two corrections to the reactor antineutrino spectrum. These corrections are generated from two specific sources and are thus named the spent nuclear fuel contribution and the non-linear correction for their respective sources. Chapter [3] contains a discussion of the spent fuel contribution. This correction arises from spent nuclear fuel near the reactor site and involves a detailed application of spent fuel to current reactor antineutrino experiments. Chapter [4] will focus on the non-linear correction, which is caused by neutron-captures within the nuclear reactor environment. Its quantification and impact on future antineutrino experiments are discussed. The research projects presented in the second half, Chapter [5], focus on neutrino applications, specifically reactor monitoring. Chapter [5] is a comprehensive examination of the use of antineutrinos as a reactor safeguards mechanism. This chapter will include the theory behind safeguards, the statistical derivation of power and plutonium measurements, the details of reactor simulations, and the future outlook for non-proliferation through antineutrino monitoring.
The Daya Bay Reactor Neutrino Experiment
Hor, Yuenkeung (Virginia Tech, 2014-09-18)
The Daya Bay experiment has determined the last unknown mixing angle $theta_{13}$. This thesis describes the layout of the experiment and the detector design. The analysis presented in the thesis covered the water attenuation, spent fuel neutrino and electron anti-neutrino spectrum. Other physics analysis and impact to future experiments are also discussed.
The Daya Bay Reactor Neutrino Experiment
Meng, Yue (Virginia Tech, 2014-09-22)
The Daya Bay reactor neutrino experiment is a high sensitivity experiment designed to determine the last unknown neutrino mixing angle $theta_{13}$ by measuring disappearance of reactor antineutrinos emitted from six 2.9 $GW_{th}$ reactors at the Daya Bay Nuclear Power Station. There are eight identical Gd-loaded liquid scintillator detectors deployed in two near (flux-weighted baseline 512 $m$ and 561 $m$) and one far (1579 $m$) underground experimental halls to detect the inverse beta decay interaction. This dissertation describes the Daya Bay Experiment and individual contributions to this experiment. Chapter 1 reviews the history of the neutrino and the neutrino oscillation phenomena. The reactor based neutrino experiments in different times are described in this chapter in detail. It presents the motivation of the Daya Bay Experiment. In Chapter 2, the neutrino detection method and the $theta_{13}$ relative measurement method are introduced. This chapter focuses on the design of the Daya Bay Experiment, including antineutrino detector, calibration system, muon veto system and muon tagging system. Chapter 3 shows the design, development, construction, and assembly of Muon Pool PMT calibration system, and presents an algorithm of calculating the muon pool PMT timing offset values. Chapter 4 focuses on the manufacture, installation and commissioning of RPC HV system. Chapter 5 presents the analyses of the radioactive isotopes induced by comic muons. The Daya Bay detector energy response model is also described in detail. The relative rate analysis results exclude a zero value from $sin^22theta_{13}$ with a significance of 7.7 standard deviation using 139 days of data, 28909 (205308) antineutrino candidates which were recorded at the far hall (near halls) and shows $sin^22theta_{13} = 0.089pm0.011$ in a three-neutrino framework. A combined analysis of the $overline nu_e$ rates and energy spectra based on the detector energy response model improved measurement of the mixing angle $sin^22theta_{13} = 0.090^{+0.008}_{-0.009}$ by using 217 days of data, 41589 (203809 and 92912) antineutrino candidates were detected in the far hall (near halls). Also the first direct measurement of the $overline nu_e$ mass-squared difference $|Delta m^2_{ee}|= (2.59^{+0.19}_{-0.20})times10^{-3}$ $eV^2$. It is consistent with $|Delta m^2_{mumu}|$ measured by muon neutrino disappearance, supporting the three-flavor oscillation model.
Detection of Antineutrinos at the North Anna Nuclear Generating Station
Li, Shengchao (Virginia Tech, 2020-10-28)
Nuclear reactors have played an essential role in developing our current understanding of neutrinos. The precision measurement of these high-flux, pure-flavor and controllable artificial neutrino sources shed lights on a wide range of fundamental questions in physics. Specifically, the Reactor Antineutrino Anomaly hints that there may exist a novel eV-scale sterile neutrino, which requires new physics beyond the Standard Model. Performing reactor neutrino spectrum measurements at very-short baseline will improve our imperfect understanding of antineutrino emission from fissile material. CHANDLER is a new-generation neutrino experiment aiming for reactor antineutrino spectrum measurements, to test the eV-scale sterile neutrino oscillation hypothesis unambiguously. The second prototype detector, MiniCHANDLER, was deployed 25 meters from a $2.9~GW_{th}$ commercial nuclear reactor in North Anna, Virginia. To fight against the overwhelming background arising from its surface-level deployment, CHANDLER detectors adopt a novel design using lithium-6 ($^6$Li) loaded zinc sulfide (ZnS) scintillator to tag neutron capture events, which significantly improves the IBD detection efficiency. The use of the Raghavan optical lattice brings enormous enhancement of light collection towards high energy resolution, which unlocks reconstruction of event topology to further suppress backgrounds. The ability of measuring reactor antineutrino spectra enables the potential application of CHANDLER technology in nuclear nonproliferation. This thesis features the prototype detectors instrumentation, data analysis development and Monte Carlo study for the CHANDLER experiment during 2016 to 2020. The detector calibration and energy reconstruction with vertical muon forms a core piece of this thesis. We report our observation of IBD spectrum with 5.5$sigma$ significance with a four month deployment of the minimal shielded MiniCHANDLER prototype at North Anna. The application of separation cuts and topological selections in the analysis are instrumental for a segmented plastic scintillator detector. We also present our results from the proton scintillation quenching measurement at Triangle Universities Nuclear Laboratory, with the deployment of the first prototype detector, MicroCHANDLER, at a neutron beam.
Determination of antineutrino spectra from nuclear reactors
Huber, Patrick (American Physical Society, 2011-08-29)
In this paper we study the effect of well-known higher-order corrections to the allowed beta-decay spectrum on the determination of antineutrino spectra resulting from the decays of fission fragments. In particular, we try to estimate the associated theory errors and find that induced currents like weak magnetism may ultimately limit our ability to improve the current accuracy and under certain circumstance could even greatly increase the theoretical errors. We also perform a critical evaluation of the errors associated with our method to extract the antineutrino spectrum using synthetic beta spectra. It turns out that a fit using only virtual beta branches with a judicious choice of the effective nuclear charge provides results with a minimal bias. We apply this method to actual data for (235)U, (239)Pu, and (241)Pu and confirm, within errors, recent results, which indicate a net 3% upward shift in energy-averaged antineutrino fluxes. However, we also find significant shape differences which can, in principle, be tested by high-statistics antineutrino data samples.
Electron Transport via Single Molecule Magnets with Magnetic Anisotropy
Luo, Guangpu (Virginia Tech, 2019-02-07)
Single molecule magnets (SMMs) are molecules of mesoscopic scale which exhibit quantum properties such as quantum tunneling of magnetization, quantum interference, spin filtering effects, strong spin-phonon coupling and strong hyperfine Stark effects. These effects allow applications of SMMs to high-density information storage, molecular spintronics, and quantum information science. Therefore, SMMs are of interest to physicists, chemists, and engineers. Recently, experimental fabrication of individual SMMs within transistor set-ups have been achieved, offering a new method to examine magnetic properties of individual SMMs. In this thesis, two types of SMMs, specifically Eu2(C8H8)3 and Ni9Te6(PEt3)8, are theoretically investigated by simulating their electron transport properties within three-terminal transistor set-ups. An extended metal atom chain (EMAC) consists of a string of metallic atoms with organic ligands surrounding the string. EMACs are an important research field for nanoelectronics. Homometallic iron-based EMACs are especially attractive due to the high spin and large magnetic anisotropy of iron(II). We explore the exchange coupling of iron atoms in two EMACs: [Fe2(mes)2(dpa)2] and [Fe4(tpda)3Cl2]. Chapter 1 provides an introduction to SMMs, electron transport experiments via SMMs and an introduction to density functional theory (DFT). Chapter 2 presents a theoretical study of electron transport via Eu2(C8H8)3. This type of molecule is interesting since its magnetic anisotropy type changes with oxidation state. The unique magnetic properties lead to spin blockade effects at zero and low bias. In other words, the current through this molecule is completely suppressed until the bias voltage exceeds a certain value. Chapter 3 discusses a theoretical study of electron transport via Ni9Te6(PEt3)8. The magnetic anisotropy of this magnetic cluster has cubic symmetry, which is higher than most SMMs. With appropriate magnetic anisotropy parameters, in the presence of an external magnetic field, uncommon phenomena such as low-bias blockade effects, negative conductance and discontinuous conductance lines, are observed. In Chapter 2 and 3 DFT-calculated magnetic anisotropy parameters are used and electron transport properties are calculated by solving master equations at low temperature. Chapter 4 examines the exchange coupling between iron ions in EMACs [Fe2(mes)2(dpa)2] and [Fe4(tpda)3Cl2]. The exchange coupling constants are calculated by using the least-squares fitting method, based on the DFT-calculated energies from different spin configurations.
Fundamental Physics at the Intensity Frontier
Hewett, J. L.; Weerts, H.; Brock, R.; Butler, J. N.; Casey, B. C. K.; Collar, J.; Gouvea, A. D.; Essig, R.; Grossman, Y.; Haxton, W.; Jaros, J. A.; Jung, C. K.; Lu, Z. T.; Pitts, K.; Ligeti, Z.; Patterson, J. R.; Ramsey-Musolf, M.; Ritchie, J. L.; Roodman, A.; Scholberg, K.; Wagner, C. E. M.; Zeller, Geralyn P.; Aefsky, S.; Afanasev, A.; Agashe, K.; Albright, C. H.; Alonso, J.; Ankenbrandt, C. M.; Aoki, M.; Arguelles, C. A.; Arkani-Hamed, N.; Armendariz, J. R.; Armendariz-Picon, C.; Diaz, E. A.; Asaadi, J.; Asner, D. M.; Babu, K. S.; Bailey, K.; Baker, O.; Balantekin, A. B.; Baller, B.; Bass, M.; Batell, B.; Beacham, J.; Behr, J.; Berger, N.; Bergevin, M.; Berman, E.; Bernstein, R.; Bevan, A. J.; Bishai, M.; Blanke, M.; Blessing, S.; Blondel, A.; Blum, T.; Bock, G.; Bodek, A.; Bonvicini, G.; Bossi, F.; Boyce, J.; Breedon, R.; Breidenbach, M.; Brice, S. J.; Briere, R. A.; Brodsky, S.; Bromberg, C.; Bross, A.; Browder, T. E.; Bryman, D. A.; Buckley, M.; Burnstein, R.; Caden, E.; Campana, P.; Carlini, R.; Carosi, G.; Castromonte, C.; Cenci, R.; Chakaberia, I.; Chen, M. C.; Cheng, C. H.; Choudhary, B.; Christ, N. H.; Christensen, E.; Christy, M. E.; Chupp, T. E.; Church, E.; Cline, D. B.; Coan, T. E.; Coloma, P.; Comfort, J.; Coney, L.; Cooper, J.; Cooper, R. J.; Cowan, R.; Cowen, D. F.; Cronin-Hennessy, D.; Datta, A.; Davies, G. S.; Demarteau, M.; DeMille, D. P.; Denig, A.; Dermisek, R.; Deshpande, A.; Dewey, M. S.; Dharmapalan, R.; Dhooghe, J.; Dietrich, M. R.; Diwan, M.; Djurcic, Zelimir; Dobbs, S.; Duraisamy, M.; Dutta, B.; Duyang, H.; Dwyer, D. A.; Eads, M.; Echenard, B.; Elliott, S. R.; Escobar, C. O.; Fajans, J.; Farooq, S.; Faroughy, C.; Fast, J. E.; Feinberg, B.; Felde, J.; Feldman, G.; Fierlinger, P.; Perez, P. F.; Filippone, B. W.; Fisher, P.; Fleming, B. T.; Flood, K. T.; Forty, R.; Frank, M. J.; Freyberger, A.; Friedland, A.; Gandhi, R.; Ganezer, K. S.; Garcia, A.; Garcia, F. G.; Gardiner, S.; Garrison, L.; Gasparian, A.; Geer, S.; Gehman, V. M.; Gershon, T.; Gilchriese, M.; Ginsberg, C.; Gogoladze, I.; Gonderinger, M.; Goodman, M.; Gould, H.; Graham, M.; Graham, P. W.; Gran, R.; Grange, J.; Gratta, G.; Green, J. P.; Greenlee, H.; Group, R. C.; Guardincerri, E.; Gudkov, V.; Guenette, R.; Haas, A.; Hahn, A.; Han, T.; Handler, T.; Hardy, J. C.; Harnik, R.; Harris, D. A.; Harris, F. A.; Harris, P. G.; Hartnett, J.; He, B.; Heckel, B. R.; Heeger, K. M.; Henderson, S.; Hertzog, D.; Hill, R.; Hinds, E. A.; Hitlin, D. G.; Holt, R. J.; Holtkamp, N.; Horton-Smith, Glenn A.; Huber, Patrick; Huelsnitz, W.; Imber, J.; Irastorza, I.; Jaeckel, J.; Jaegle, I.; James, C.; Jawahery, A.; Jensen, D.; Jessop, C. P.; Jones, B.; Jostlein, H.; Junk, T.; Kagan, A. L.; Kalita, M.; Kamyshkov, Y.; Kaplan, D. M.; Karagiorgi, Georgia S.; Karle, A.; Katori, T.; Kayser, B.; Kephart, R.; Kettell, S. H.; Kim, Y.-K.; Kirby, M.; Kirch, K.; Klein, J.; Kneller, J.; Kobach, A.; Kohl, M.; Kopp, J.; Kordosky, M.; Korsch, W.; Kourbanis, I.; Krisch, A. D.; Križan, P.; Kronfeld, A. S.; Kulkarni, S.; Kumar, K. S.; Kuno, Y.; Kutter, T.; Lachenmaier, Tobias; Lamm, M.; Lancaster, J.; Lancaster, M.; Lane, C.; Lang, K.; Langacker, P.; Lazarevic, S.; Le, T.; Lee, K.; Lesko, K. T.; Li, Y.; Lindgren, M.; Lindner, A.; Link, Jonathan M.; Lissauer, D.; Littenberg, L. S.; Littlejohn, B.; Liu, C. Y.; Loinaz, William; Lorenzon, W.; Louis, W. C.; Lozier, J.; Ludovici, L.; Lueking, L.; Lunardini, C.; MacFarlane, D. B.; Machado, P. A. N.; Mackenzie, P. B.; Maloney, J.; Marciano, W. J.; Marsh, W.; Marshak, M.; Martin, J. W.; Mauger, C.; McFarland, K. S.; McGrew, C.; McLaughlin, G.; McKeen, D.; McKeown, R.; Meadows, B. T.; Mehdiyev, R.; Melconian, D.; Merkel, H.; Messier, M.; Miller, J. P.; Mills, G.; Minamisono, U. K.; Mishra, S. R.; Mocioiu, I.; Sher, S. M.; Mohapatra, R. N.; Monreal, B.; Moore, C. D.; Morfin, J. G.; Mousseau, J.; Moustakas, L. A.; Mueller, G.; Mueller, P.; Muether, M.; Mumm, H. P.; Munger, C.; Murayama, H.; Nath, P.; Naviliat-Cuncin, O.; Nelson, J. K.; Neuffer, D.; Nico, J. S.; Norman, A.; Nygren, D.; Obayashi, Y.; O'Connor, T. P.; Okada, Y.; Olsen, J.; Orozco, L.; Orrell, J. L.; Osta, J.; Pahlka, B.; Paley, J.; Papadimitriou, V.; Papucci, M.; Parke, S.; Parker, R. H.; Parsa, Z.; Partyka, K.; Patch, A.; Pati, J. C.; Patterson, R. B.; Pavlovic, Z.; Paz, G.; Perdue, G. N.; Perevalov, D.; Perez, G.; Petti, R.; Pettus, W.; Piepke, A.; Pivovaroff, M. J.; Plunkett, R.; Polly, C. C.; Pospelov, M.; Povey, R.; Prakash, A.; Purohit, M. V.; Raby, S.; Raaf, J. L.; Rajendran, R.; Rajendran, S.; Rameika, G.; Ramsey, R.; Rashed, A.; Ratcliff, B. N.; Rebel, B.; Redondo, J.; Reimer, P.; Reitzner, D.; Ringer, F.; Ringwald, A.; Riordan, S.; Roberts, B. L.; Roberts, D. A.; Robertson, R.; Robicheaux, F.; Rominsky, M.; Roser, R.; Rosner, J. L.; Rott, C.; Rubin, P.; Saito, N.; Sanchez, Maria Cristina; Sarkar, S.; Schellman, H.; Schmidt, B.; Schmitt, M.; Schmitz, D. W.; Schneps, J.; Schopper, A.; Schuster, P.; Schwartz, A. J.; Schwarz, M.; Seeman, J.; Semertzidis, Y. K.; Seth, K. K.; Shafi, Q.; Shanahan, P.; Sharma, R.; Sharpe, S. R.; Shiozawa, M.; Shiltsev, V.; Sigurdson, K.; Sikivie, P.; Singh, J.; Sivers, D.; Skwarnicki, T.; Smith, N.; Sobczyk, J.; Sobel, H.; Soderberg, M.; Song, Y. H.; Soni, A.; Souder, P. A.; Sousa, A.; Spitz, Joshua; Stancari, M.; Stavenga, G. C.; Steffen, J. H.; Stepanyan, S.; Stoeckinger, D.; Stone, S.; Strait, J.; Strassler, M.; Sulai, I. A.; Sundrum, R.; Svoboda, R.; Szczerbinska, B.; Szelc, A.; Takeuchi, Tatsu; Tanedo, P.; Taneja, S.; Tang, J.; Tanner, D. B.; Tayloe, R.; Taylor, I.; Thomas, J.; Thorn, C.; Tian, X.; Tice, B. G.; Tobar, M.; Tolich, N.; Toro, N.; Towner, I. S.; Tsai, Y.; Tschirhart, R.; Tunnell, C. D.; Tzanov, M.; Upadhye, A.; Urheim, J.; Vahsen, S. E.; Vainshtein, A.; Valencia, E.; Water, R. G. V. D.; Water, RSVD; Velasco, M.; Vogel, J.; Vogel, P.; Vogelsang, W.; Wah, Y W.; Walker, D.; Weiner, N.; Weltman, A.; Wendell, R.; Wester, W.; Wetstein, M.; White, C.; Whitehead, L.; Whitmore, J.; Widmann, E.; Wiedemann, G.; Wilkerson, J.; Wilkinson, G.; Wilson, P.; Wilson, R. J.; Winter, W.; Wise, Milton B.; Wodin, J.; Wojcicki, S.; Wojtsekhowski, B.; Wongjirad, T.; Worcester, E.; Wurtele, J.; Xin, T.; Xu, J.; Yamanaka, T.; Yamazaki, Y.; Yavin, I.; Yeck, J.; Yeh, M.; Yokoyama, M.; Yoo, J.; Young, A.; Zimmerman, E.; Zioutas, K.; Zisman, M.; Zupan, J.; Zwaska, R. (2011)
The Proceedings of the 2011 workshop on Fundamental Physics at the Intensity Frontier. Science opportunities at the intensity frontier are identified and described in the areas of heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms.
Future searches for light sterile neutrinos at nuclear reactors
Berryman, Jeffrey M.; Delgadillo, Luis A.; Huber, Patrick (American Physical Society, 2022-02-02)
We study the optimization of a green-field, two-baseline reactor experiment with respect to the sensitivity for electron antineutrino disappearance in search of a light sterile neutrino. We consider both commercial and research reactors and identify as key factors the distance of closest approach and detector energy resolution. We find that a total of 5 tons of detectors deployed at a commercial reactor with a closest approach of 25 m can probe the mixing angle sin(2) 2 theta down to similar to 5 x 10(-3) around Delta m(2) similar to 1 eV(2). The same detector mass deployed at a research reactor can be sensitive up to Delta m(2) similar to 20-30 eV(2) assuming a closest approach of 3 m and excellent energy resolution, such as that projected for the Taishan Antineutrino Observatory. We also find that lithium doping of the reactor could be effective in increasing the sensitivity for higher Delta m(2) values.
Inclusive and exclusive electron scattering data analysis from Jefferson Lab experiment E12-14-012
Murphy, Matthew Douglas (Virginia Tech, 2021-01-19)
Since the first observations of neutrino oscillation, neutrino experiments have come a long way toward precise measurements of the neutrino oscillation parameters, but some obstacles still remain. The next generation of oscillation experiments, including the Deep Underground Neutrino Experiment (DUNE), will be using the Liquid Argon Time Projection Chambers (LArTPCs) with natural argon as the neutrino target material. A precise model of the neutrino cross section on argon does not exist, which is a source of significant uncertainty in such experiments. The E12-14-012 experiment at Jefferson Lab seeks to help remedy this via electron scattering measurements on argon and titanium targets. The experiment collected both inclusive (e,e') and exclusive (e,e'p) data at a wide range of kinematics with the intent to measure the electron-nucleus cross section and thus derive a spectral function for argon that can be used with neutrino experiments. The use of titanium in this experiment stems from the equivalent shell structure that its protons share with the neutrons in argon, which will be crucial in oscillation experiments but cannot be measured directly in electron scattering. This thesis collects several papers which present results from the E12-14-012 experiment. These results include the inclusive (e,e') cross sections for carbon, titanium, argon, and aluminum at a beam energy of 2.22 GeV and a scattering angle of 15.54 deg with uncertainty of less than 5%. Also included are the first results of the exclusive (e,e'p) cross section on argon and titanium.

Browsing by Author "Huber, Patrick"

Results Per Page

Sort Options